Picking up an iPhone 5 on Sprint is tempting, since it's the only carrier offering new unlimited plans. However, buyers should know that of the three carriers, Sprint has the smallest 4G service area by far. Buy an iPhone 5 on Sprint and you'll basically pay for unlimited 3G service until Sprint brings 4G LTE to your area.

iPhone 5 on Sprint's 4G LTE network

As mentioned, Sprint is currently the only carrier offering unlimited data plans to new customers for the iPhone 5. Other carriers will let you remain "grandfathered in" on an old unlimited plan, but new iPhone customers will be out of luck.

For the iPhone 5, all Sprint plans come with unlimited data and text messaging. All that's left to choose is talk time, with options for 450 or 900 anytime minutes at $79.99 and $99.99 a month, respectively. Unlimited talk goes for $109.99.

Slim 4G coverage

Perhaps Sprint can be so liberal with the offers of unlimited data because its 4G coverage is rather limited, compared to its competitors. Sprint launched its LTE network a little over two years ago, but major U.S. cities such as New York City, Boston, San Francisco, Chicago and Los Angeles are still without 4G service.

However, customers in the regions of Baltimore, Atlanta, Kansas City and parts of Texas are in luck.

They live in the in areas of the U.S. that actually have 4G Sprint service right now. For them, the iPhone 5 on Sprint is a great deal.

Sprint's website says that 4G will come to other regions of the U.S. "in the coming months," but has not released any hard dates. TechRadar has reached out to Sprint for a timeline on its 4G rollout and we will update this article when we receive a response.

4G isn't everything

Of course, just because you don't have 4G doesn't mean you're not using the latest iOS 6 Apple toy. Still, it's rather irksome to think that you'll pay the same monthly bill as a customer in Atlanta or Dallas who's enjoying 4G speeds.

However, FaceTime over cellular service, which has become a major point of contention for AT&T and Verizon, is far more straightforward with Sprint. Sprint customers will be able to FaceTime over 3G and 4G at no additional cost, without being forced into shared data plans.

Verdict

There's a lot to like about the iPhone 5 on Sprint, and a lot to dislike, especially if you live in the parts of the U.S. without its 4G service.

We like that Sprint's plans are easy to understand, and that they come with unlimited data, text messaging and FaceTime over cellular. We don't like how limited Sprint's 4G coverage area is, and the fact that 3G customers will pay the same rate as those with 4G.

You're basically choosing between unlimited data with Sprint, or 4G speeds with AT&T or Verizon, unless you live in those lucky parts of the U.S. with Sprint 4G, in which case you can have it all.

It's hard to believe a phone so thin could offer so many features: a larger display, a faster chip, the latest wireless technology, an 8MP iSight camera, and more. All in a beautiful aluminum body designed and made with an unprecedented level of precision. iPhone 5 measures a mere 7.6 millimeters thin and weighs just 112 grams. That's 18 percent thinner and 20 percent lighter than iPhone 4S. The only way to achieve a design like this is by relentlessly considering (and reconsidering) every single detail - including the details you don't see.